A
Our world is full of wonders, making us feel excited and curious. Let's take a look at the following three unusual sights(景象).
(
) 1. What really causes red rain?
A. Tiny red plants.
B. Red clouds in the sky.
C. Red dust from deserts.
D. Special light from nature.
(
) 2. Which of the following could be the best title for the blank?
A. Cold winter rivers
B. Slow-moving plates
C. Dangerous round ice
D. Amazing ice circles
(
) 3. What do the three sights have in common?
A. They are all connected with water.
B. They all happen in desert areas.
C. They all need strong winds to form.
D. They all happen in winter.
解析：
1. 细节理解题。定位到"Red rain from the sky"部分的内容"But now we know it's usually from red dust(灰尘) from faraway deserts mixing with rainwater"，可知红雨的真正成因是来自沙漠的红色灰尘和雨水混合，对应选项C。
2. 标题判断题。空白处对应的段落核心介绍自然奇观冰圈的形态和形成过程，和前文两个介绍奇观的小标题风格呼应，D选项"Amazing ice circles"完全贴合段落核心内容，其余选项都无法概括该段内容，选D。
3. 推理判断题：乳状云的形成和云中的小水滴有关，红雨是红色灰尘和雨水混合形成，冰圈是水中的冰块被水流打磨形成，三处奇观都和水有关。其余选项：B只有红雨和沙漠相关，C文中没有提及三者都需要强风，D乳状云和红雨并不只发生在冬季，表述均错误，选A。
